package xyz.fefine;

import java.util.Iterator;

/**
 * Created by feng_ on 2016/9/2.
 * 语法树的节点类
 */
public abstract class ASTree {
    public static final int TRUE = 1;
    public static final int FALSE = -1;
    public abstract ASTree child(int i);
    public abstract int numChildren();
    public abstract Iterator<ASTree> children();
    public abstract String location();
    public Iterator<ASTree> iterator(){return children();}

    public abstract Object eval(Enviorment enviorment);

    public void lookup(Symbols syms){}

}
